Lipid nanoparticles for the delivery of ginger oil and hexylresorcinol in the treatment of cutaneous hyperpigmentation

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INTRODUCTION
Cosmetics are defined by EUR lex 1223/2009 and the FDA as “articles intended to be applied to the human body or any part thereof for cleansing, beautifying, promoting attractiveness, or altering the appearance” (1,2). Cosmetics must be safe for consumers and Companies and individuals who market cosmetics have a legal responsibility for the safety and labeling of their products. The term “cosmeceutical” was coined in 1984 by Dr. Albert Kligman of the University of Pennsylvania describing a hybrid category of products mid-way on the spectrum of ‘cosmetics and pharmaceutical.’ A cosmeceutical is consensually accepted to exert a ‘pharmaceutical therapeutic benefit’ but not necessarily a ‘biological therapeutic benefit.’ For Dr. Kligman, cosmeceutical represented a topical preparation that is sold as a cosmetic but has performance characteristics that suggest pharmaceutical action. Cosmeceuticals are the fastest-growing segment of the personal care industry, and several topical treatments for conditions such as photoaging, hyperpigmentation, wrinkles, and hair damage have come into widespread use. Nanotechnology plays an important new perspective for the future of the cosmeceutical industry and offers the advantage of diversity in products, and increased bioavailability of active ingredients (3). Some of the nanotechnology-based innovations are nanoemulsions (which are transparent and have unique tactile and texture properties), nanocapsules (which are used in skin care products), nanopigments (that are transparent and increase the efficiency of sunscreen products), liposome formulations (which contain small vesicles consisting of conventional cosmetic materials that protect oxygen or light sensitive cosmetic ingredients), niosomes, nanocrystals, solid lipid nanoparticles, carbon nanotubes, fullerenes, and dendrimers. The primary advantages of using nanoparticles in cosmeceuticals include improvement in the stability of cosmetic ingredients (e.g., vitamins, unsaturated fatty acids, and antioxidants) by encapsulating within the nanoparticles; efficient protection of the skin from harmful ultraviolet (UV) rays; aesthetically pleasing products, targeting of active ingredient to the desired site and controlled release of active ingredients for prolonged effect (4).